A watch has one basic job: to tell you the time.
It seems simple. However, as you know from reading these blog posts, you know there are hundreds of small parts all moving in unison to tell you the time and make sure you’re not late for your big meeting or dinner at your in-laws.
A watch complication is anything that a watch does other than tell you what time it is. They’re called that because they, well, make the watch more complicated than just telling you the time. These additions are designed to make your life easier (John Swigert’s Omega Speedmaster helped save his and his crewmates’ lives aboard Apollo 13) or to simply enhance it (heart rate monitors and step counters would fit here).
Several complications are available in watches, like simple date displays or more complex functions such as a tourbillon or repeater.
Here are some examples of complications in watches.